Approximately one person in 400 each year suffers from some kind of impairment related to head trauma. By finding significant changes in the brain that were environmentally-induced after trauma would have a great impact on the brain function and recovery after trauma. The long-term objectives of this proposal are to determine anatomical, biochemical and cellular changes which take place within the brain following both early and late brain damage and to train minority students in the area of mental health. The specific aims are (1) to determine if damage to neocortical structures in the brain of neonatal and aged rats remain permanent (2) to determine the anatomical, biochemical, cellular/molecular changes that occur in the brain (neocortex, septum and hippocampus) after injury and subsequent exposure to differential environments and (3) to train undergraduate students in research methods of cellular and molecular biology which they can use in mental health professions. The experience from this endeavor by minority students will better prepare them for graduate training and increase their numbers in mental health professionals. Specific Aims I and II will be accomplished by inflicting neocortical lesions (right, left and sham) in rat pups and adults. Subsequently, the animals will be exposed to "enriched or impoverished" environments, the brains removed and the following parameters assessed: (1) brain weight, (2) determination of different brain cell types, (3) DNA and protein content, (4) changes in protein synthesis (5) changes in structural and microtubular proteins (6) morphological changes in the brain, and (7) changes in the presence of neurotransmitters. These various parameters will be investigated by using the following techniques: proteins biochemistry, 1 and 2-D gel electrophoresis, Western blotting, indirect immunofluorescence, immunocytochemistry, ligand binding assays, light, transmission and scanning electron microscopy. The training of undergraduate students will be an integral part of this proposal. The students will be involved in every aspect of the project from animal handling, conducting experiments, writing manuscripts and presentations at scientific meetings.